Anti-tax avoidance activists took control of a central London retailer and intimidated staff and customers during an occupation in March, a court has heard.

Ten members of UK Uncut, aged between 19 and 42, are on trial at Westminster magistrates court for aggravated trespass during the occupation of Fortnum & Mason involving over 150 activists.

It is alleged that the 10 defendants were especially disruptive inside the store and played an organising role. Some were accused of playing the bagpipes, others of playing catch with a football-sized beach ball and carrying banners.

The court saw CCTV footage showing UK Uncut demonstrators entering the ground floor of the store, on Piccadilly, just after 4pm on 26 March.

In his opening statement, prosecuting barrister David Malone said: "They are collectively taking control of the premises …taking control of the doors."

He added that a chant – "If you don't pay your taxes we'll shut you down" – was also indicative of the group's intention to take control of the premises.

In the footage some protesters were seen wearing masks and others waving flags or banners.

Malone told the court that people who were filmed defacing the front of the store with chalk graffiti and causing other damage were not connected with protesters inside the store. "There is nothing to link those individuals [outside the store] to UK Uncut," he said.

He added that by being forced to close early, Fortnum & Mason had suffered a loss in sales of between £54,000 and £68,000.

Speaking about one defendant, 25-year-old Daniel Lichman, who was alleged to have been filmed playing with a beach ball inside the store, Malone said: "On a normal day no one would be able to do that."

Outside Westminster magistrates court building in Marylebone, there was a demonstration of around 30 people in support of the defendants.